Cis-3-hexenyl butyrate as an attractant for yellow jackets

ABSTRACT

THE INSECT ATTRACTANTS OF THE PRESENT INVENTION ARE HIGHLY SPECIFIC FOR YELLOW JACKETS (VESPULA SPP.), ATTRACTING FEW OTHER INSECTS AND NO BENEFICIAL SPECIES SUCH AS HONEY BEES. THESE ATTRACTANTS ARE ORGANIC ESTERS HAVING A TOTAL OF FROM 9 TO 12 CARBON ATOMS, AND THEY HAVE AT LEAST ONE CENTER OF UNSATURATION, AS EXEMPLIFIED BY CIS-3HEXENYL BUTYRATE AND 2-METHYLEPENTYL CROTANATE, OR AN ALICYCLIC RADICAL AS IN 4-METHYLCYCLOHEXYL BUTYRATE, THE ESTER, 2,4-HEXADIENYL BUTYRATE, WAS OUTSTANDING IN FIELD TESTS. INCORPORATED INTO COMPOSITIONS CONTAINING AN INSECTICIDE, CHEMOSTERILANT OR OTHER CONTROL AGENT, THE ATTRACTANTS PROVIDE AN IMPROVED MEANS OF REDUCING ELIMINATING POPULATIONS OF YELLOW JACKETS.

United States Patent O1 3,790,666 Patented Feb. 5, 1974 Int. Cl. A01n 17/14 US. Cl. 424-84 1 Claim ABSTRACT OF THE DISCLOSURE The insect attractants of the present invention are highly specific for yellow jackets (Vespula spp.), attracting few other insects and no beneficial species such as honey bees. These attractants are organic esters having a total of from 9 to 12 carbon atoms, and they have at least one center of unsaturation, as exemplified by cis-3- hexenyl butyrate and Z-methylpentyl crotanate, or an alicyclic radical as in 4-methylcyclohexyl butyrate. The ester, 2,4-hexadienyl butyrate, was outstanding in field tests. Incorporated into compositions containing an insecticide, chemosterilant or other control agent, the attractants provide an improved means of reducing or eliminating populations of yellow jackets.

A nonexclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This application is a division of our pending application for patent, Ser. No. 857,611 filed June 27, 1969, now abandoned which is a division of Ser. No. 623,154 filed Dec. 29, 1966, now Pat. No. 3,485,868, issued Dec. 23, 1969.

This invention relates to compounds useful for attracting yellow jackets (Vespula spp.), which are insects of medical and pestiferous importance. The invention relates further to combinations of these attractants with insect control agents, such as insecticides, chemosterilants, and the like to provide the respective attractant compositions.

According to one authority hymenopterous insects caused almost 50% of the 460 deaths attributed to venomous animals in the United States between 1950 and 1959. Of these almost 5% were caused by yellow jackets. However, these fatalities represent only a small percentage of the number of persons attacked, hospitalized, or otherwise imposed upon by these insects. Inasmuch as attractants have proved very useful as an aid in controlling other insect pests, it is anticipated that attractants would be useful similarly in combating yellow jackets. For example, the attractant may be used in a trap,

poisonous bait, or distributed with a toxicant on a carrier. One of the especially desirable features of using attractants for control is that very little of the insecticide or insect control agent is required. The use of the instantly claimed attractants would be most efiicient because such problems as do arise with yellow jackets often occur in a localized area. Attractants have a further advantage in that they can be used to lure the insects to their death, while at the same time, offering practically no chemical hazards to man, animals, or plants. The attractants herein described have still another desirable feature, in that they are highly specific for yellow jackets. They attracted few other insects, most of which were considered accidental catches, and no beneficial species such as honey bees.

An object of the present invention is to provide attractants for use in reducing or eliminating populations of yellow jackets. Another object is to provide yellow jacket a-ttractants that are highly specific for this insect. A further object is to provide chemical yellow jacket attracta-nts suitable for inclusion in composition with insecticides, chemosterilants, and other insect control agents. Other objects will be apparent upon inspection of the specification and claims.

We have discovered that certain organic esters are highly specific as attractants for yellow jackets.

According to the present invention an attractant for yellow jackets comprises an ester having an alcohol moiety (part) and an acid moiety, the ester having a total of from 9 to 12 carbon atoms per molecule, in which ester at least one of the moieties is aliphatic with at least one center of unsaturation or is alicyclic.

In a preferred embodiment of the invention the alcohol moiety of the organic ester is derived from an unsaturated aliphatic alcohol having five to seven carbon atoms, especially the 2,4-hexadienyl and cis-S-hexenyl groups (radicals), or is an alicyclic group such as cyclohexyl or 4-methylcyclohexyl.

In another embodiment of the present invention the center of unsaturation is in an aliphatic acid moiety of the ester, as in certain acrylates, methacrylates, crotonates sorbates, and heptynoates. The ester can also have unsaturation in both the alcohol and acid moieties, as in 2,4-hexadienyl esters of crotonic or tiglic acid.

The attractiveness for yellow jackets of the esters of the present invention was demonstrated by practical field tests. In a typical test, about 0.25 gram of the ester to be evaluated and 2 ml. of acetone were placed in the bottom of a pint glass jar which was rotated to distribute the compound. The jar was capped with an inverted screen cone having a /2 inch diameter hole at the apex of the cone. The jars were then placed in the field 1 to 2 feet apart on boards positioned about 3 feet off the ground.

Tests were usually started at noon and terminated 2.4 or more hours later. Insects responding to the candidate lures entered the /z-inch orifice and were then unable to escape the traps.

Other aspects of testing, such as varying the amount of attractant, the time factors, and use of controls, are illustrated by the field test data presented in Table 1.

jackets were synthesized for use in the field tests. The esters were prepared by reacting an alcohol with an acid chloride using pyridine as a hydrochloric acid scavenger. A typical procedure is illustrated by the following descripalcohol moiety are 2,4-hexadienyl butyrate and cis-3-hexenyl butyrate, both containing a total of carbon atoms. This number of carbon atom is also contained in the best of the esters having an unsaturated acid moiety, Z-methylpentyl crotonate. The pentyl and isopentyl esters of 5 tron of the preparation of 2,4-hexad1enyl dl-2-methylbutyr- 2-heptyno1c acid (Table 6, Nos. 3 and 5) having 12 carate: bon atoms in the ester, are also among the better atdl-2-methylbutyryl chloride, 12.1 grams, was added tractants. dropwise to an ice cold solution of 2,4-hexadien-1-ol, 9.8 grams and pyridine, 8 grams, in 100 ml. of benzene. The 10 solution was stirred vigorously during the addition and TABLE 4 for 1 hour after the addition was pompleted' Ether was Comparison of some 2,4-hexadieny1 esters asyellowjacket attractants in added (ca. 150 m1.) and the organic layer was extracted 24-hour field tests with water until the Wash was neutral to litmus paper. The Attrw Carbon organic layer was dried over magnesium sulfate, filtered, tiveness atoms and the ether and benzene removed under reduced pres- Commlmd numb in ester sure (water pump). After the addition of a small amount 1 Acetate- 0 8 of hydroquinone the crude ester was distllled under high Pmplmm 9 3 Isobutyrate 42 10 vacuum to give 13.4 grams of product WhlCh had the fol- 4- Butym 100 10 lowing constants: B.P. 56-7/0.6 mm., 21 1.4646. g @gggg g Chemical and physical constants of compounds not 71 Isovalera te 2a 11 8 Pivalatn 17 11 previously described in the literature are presented 1H 9 Hexanoate 0 12 Table 2. Also, the purity of the esters was checked by gas chromatography.

While the attractants of the present invention are not TABLE 5 h h 1 h Relative attractiveness to ellow ackets of esters in whic t e aco 01 indicated to attract other insects, they are generally applrc moiety is gnsatugated or alicyclic able to yellow ackets. As shown in Table 3, the species Vespula atropilesa, Vespula pensylvanica and Vespula Compound i i 52 3%;; vulgaris were collected in the area of Willamette Valley of number Ester rating in ester Oregon and m ml ps and Pe er Rope Lake, RC, 1 cisahexenylbutyme 73 10 Canada. In addition, three other species of vespula were 2 4-methylcyclohexylbutyrate. 38 11 collected in tests conducted in the eastern part of the 51""- at United States. 22 10 6-.- 2o 10 TABLE 3 Data pertaining to species of yellow iaekets attracted to 2,4-hexadienyl butyrate dunng tests conducted over a three-week period 10 Date 111: 1 9 10 collected, 12. I 1,3-dimethyl-2-butenyl butyrate 7 10 p s 1965 Location 13 l-propyl-tl-butenyi butyrate 7 11 4O 14.. 3-methyleyclohexyl butyrate- 5 11 Vespalu 11101117080 9/9 Sisters, Oregon, 15 l-propylallyl butyrate 4 10 Vespala atropilosa, 9 23 Marys Peak, Oregon. 16 2-p py y1 ty 0 7 V. pensylranica Corvallis, Oregon. V. pensylvanicauu 9/9 Marys Peak, Oregon. 24-honr test; 2,4-hexadionyl butyrate=100. V. pensylmmtcm-.. 9/9 Sweethome, Oregon. 3. penspgvan cafl ianiiztirgkJurct Oregon. TABLE 6 8718!] UGTLZCG e V. getter/Iranian 9/9 Sisters, o i-ego ri f Relative attractiveness to yellow jackets of esters in which the acid V. pensylvanica 9/15 Burns, Oregon. moiety is a,B-unsaturated or alicyclic V. pensylvanica" 9/16 LaGrande, Oregon. V. pensylvanicm 9/16 Pendleton, Oregon. Attme' V. pensylvanica 9/23 Alsea, Oregon. 00111 11nd tiveness Carbon V. pensylvanica 9/29 Peter Hope Lake, 18.0,, Ca ada, num er Ester rating atoms V. penstflpan'lcau 9/30 Kamloops, 13.0., Canada. Wlgflm; 9/30 Marys Peak, Oregon. 1 2-methylpentyl crotonate 69 10 5O 2-. 2,4-hexadienyl crotonate.- 10 1 Collections on many dates at this site. 3 Pentyl 2-hcptynoate 48 12 3-butynyl 2-heptynoate- 40 11 Isopentyl Z-heptynoate... 40 As evident from the data, particularly the field tests of gf fgf f fig g flg 3g 10 Sept. 15 and Oct. 1, of Table 1, the 2,4-hexadienyl esters 2C-etliy1l1hexyl aei t iat a fig i6 Y0 O QXY 010 0113, 6 of butyric, isobutyric and propiomc acids are potent at Anylcychhexanecarboxyl 17 m tractants for yellow ackets. In these and other field tests, 2?:4-he1xadl8n1yltiglatenn- 1% 1 uty sor a e 2,4 hexadrenyl butyrate was the most effective attractant. 13 4 methy1cyc1ohexy1acmate 12 10 For purposes of rating the materials tested, 2,4-hexadienyl butyrate has been assigned a value of 100 and the other compounds have been rated in comparison with it.

In Table 4, which summarizes data regarding a series of 2,4-hexadienyl esters, the attractiveness rating of each ester was determined by dividing the number of yellow jackets caught in traps containing that ester by the member caught in traps containing 2,4-hexadienyl butyrate under otherwise similar test conditions and then multiplying by 100.

The data of Table 4 shows that in the 2,4-hexadienyl series the acid moiety should contain 3 to 5 carbon atoms, a total of 9 to 11 carbon atoms per molecule of ester. Tables 5 and 6 contain other esters in which unsaturation is present or which have an alicyclic group. The effective yellow jacket attractants of these tables have from 9 to 12 carbon atoms, usually 10 or 11, per ester molecule. The most potent attractants having unsaturation in the Some of the compounds contain centers of unsaturation in both the alcohol and acid moieties, as in 2,4-hexadienyl crotonate, 3-butynyl Z-heptynoate or 2,4-hexadienyl tiglate (Table 6, Nos. 2, 4 and 11). Others have combinations of a center of unsaturation and an alicylic group, as in l-ethynylcyclohexyl acetate (Table 5, No. 6), cyclohexyl crotonate (Table 6, No. 9), or allyl cyclohexanecarboxylate (Table 6, No. 10). While these are active compounds, they are not as etfective yellow jacket attractants as many esters containing a sole unsaturated aliphatic radical in the molecule.

The esters of the present invention are highly specific for yellow jackets. None of the various species of beneficial insects such as honey bees were caught by or seen hear any of the materials tested.

These yellow jacket attractants can be formulated with materials commonly used in insect control art, such as baits, carriers, insecticides, chemosterilants, and other additives. Insecticides for yellow jackets useful in baits are compounds such as dimethyl(2,2,2-trichloro-l-hydroxyethyl) phosphonate, 2,2-dichlorovinyl dimethyl phosphate, and 1,2-dibromo-2,2-dichloroethyl dimethyl phosphate. The use of slow-acting insecticides or of chemosterilants in thee attractant composition allows the yellow jacket to return to the nest, providing a more afiective means of controlling yellow jacket population than trapping.

We claim:

1. A method of attracting yellow jackets comprising exposing said yellow jackets to an effective attractant amount of the compound, cis-3-hexenyl butyrate.

References Cited UNITED STATES PATENTS 1/1963 Butenandt et a1 424-84 OTHER REFERENCES Chemical Abstracts, vol. 62 (1965), p. 3879h.

SAM ROSEN, Primary Examiner V. D. TURNER, Assistant Examiner 

